Desmodromic Twin Cam 4V 124cc Kit, 2-Bearing Crankshaft, Monkey, Gorilla

【SP武川 01-06-0044 Desmodromic Twin Cam 4V 124cc Kit, 2-Bearing Crankshaft, Monkey, Gorilla, Big Bore Engine Parts, Takegawa】
■Product Description
This kit features a Desmodromic Twin Cam 4V cylinder head.
124cc, 2-bearing crankshaft.
Bore diameter: 54mm
Stroke volume: 54mm
Compression ratio: 12.6:1
Recommended camshaft included

■Detailed Description
●Desmodromic Engine (Forced Valve Opening/Closing Mechanism)
The majority of motorcycles use a camshaft and valve springs to open and close their intake and exhaust valves.
The desmodromic mechanism forcibly opens and closes the valves using a special cam profile and rocker arms. Since there are no valve springs, valve surge does not occur at high RPMs, and friction related to camshaft drive is very low.
The SP Takegawa Desmodromic Twin Cam 4V is designed with eight rocker arms and two camshafts precisely arranged within the limited stud bolt positions of a Monkey engine, like a precision machine.
With the characteristics of the desmodromic mechanism combined with SP Takegawa's cylinder head development technology, it achieves top-class intake and exhaust efficiency and high engine performance.
The Twin Cam Desmodromic 4V offers high power characteristics and engine response like you've never experienced before.
●Valve Diameter: Intake: 22mm x 2 / Exhaust: 19mm x 2
The exhaust port is positioned the same as on a Monkey (carburetor model), allowing the use of standard muffler lineups instead of dedicated mufflers.
●Aluminum Billet Cylinder Head Cover
All cylinder head covers are machined from aluminum and feature a silver anodized finish with excellent corrosion resistance. The anodized finish also highlights the aluminum billet parts, giving the cylinder head a beautiful appearance.
A breather union is included for use with a breather hose.
●M8 Spark Plug
An M8 spark plug is adopted to achieve an optimal valve angle due to the 4-valve design and a more compact head.
●Rocker Arm (Forced Valve Opening/Closing Mechanism)
Without valve springs, the camshaft forcibly opens and closes the valves.
Compared to valve spring systems, this reduces resistance in the valve train and eliminates valve surge at high RPMs, allowing for high power output and engine response in the high RPM range.
(A spring is provided only on the closing side to ensure the valve seats tightly.)
●Hollow Camshaft
The camshaft for the forced valve opening/closing mechanism has separate cam lobes for opening and closing actions.
The camshaft journals are supported by ball bearings at both ends, reducing friction resistance on the camshaft during startup and at low speeds.
The included camshaft is a recommended camshaft suitable for each displacement.
●Ceramic Plated Cylinder / Piston
The 124cc uses an HA cylinder with a bore diameter of 54mm.
It employs an all-aluminum ceramic plated cylinder with excellent durability, airtightness, and heat dissipation.
The cylinder comes standard with a temperature sensor mounting port.
You can measure the cylinder temperature by purchasing an SP Takegawa thermometer-equipped meter or a thermometer.
For 124cc HA cylinder: M5 temperature sensor
The 124cc uses a forged piston.
●X-section connecting rod 54mm stroke-up crankshaft (R-Type)
Uses an X-section connecting rod. Machined from forged material, it features an X-section shape.
While reducing weight, it ensures sufficient strength, significantly improving the diffusion of buckling stress and torsional rigidity.
A special bearing with an enlarged inner diameter for the crankshaft journal bearing is adopted.
This allows the shaft diameter of the journal part, where stress concentrates on the crankshaft, to be increased from 20mm to 22mm, thereby enhancing shaft strength.

■Compatible Models
HONDA
12V Monkey/Gorilla (Z50J-2000001~/AB27-1000001~1899999)

■Notes
※Images are for illustration purposes only. Includes products with different sizes and colors.
※Product design and specifications are subject to change without notice. Please be aware.
※When installing the 124cc kit, modification of the crankcase is required.
※When installing the Desmodromic Twin Cam 4V cylinder head, the engine becomes longer, and since the engine will interfere with the tire with the stock front fork and stock top bridge & stem, changes to the front end are necessary.
※For Monkey/Gorilla, simultaneous installation of various SP Takegawa front fork kits is recommended.
※This product is made-to-order, so cancellations after ordering are not possible.
※This is a made-to-order product, so delivery may take some time. Also, please note that the manufacturer may discontinue the product or change specifications without prior notice. Thank you for your understanding.